1、从数据表t1中把那些id值在数据表t2里有匹配的记录全删除掉
DELETE t1 FROM t1,t2 WHERE t1.id=t2.id 或DELETE FROM t1 USING t1,t2 WHERE t1.id=t2.id
2、从两个表中找出相同记录的数据并把两个表中的数据都删除掉
DELETE t1,t2 from t1 LEFT JOIN t2 ON t1.id=t2.id WHERE t1.id=25
3、删除三张表中,指定字段值相同的数据;
delet t1,t2,t3 from t1 left join t2 on t1.id=t2.id inner join t3on t3.id=t1.id where t1.id=xxxx